Validation of Simple Screening test for Dementia in the Elderly: The Time and Change Test

ABSTRACT

BACKGROUND: Dementia has emerged as a leading public health problem with elderly persons and its early detection is important for treatment in curable cases. Although dementia screening tests are available, they are still complex and time consuming in practice and therefore difficult to use. Our goal was to validate the time and change(T&C) test, a simple, standardized method for detecting dementia in the elderly populations. METHODS: Participants were 59 patients aged 65 years or older at an urban hospital from November 1 to December 31, 2001. The time test evaluated the understanding of clock hands indicating 1110, and the change test the ability making 1,000 Won from a group of coins consisting one 500 Won, seven 100 Won, seven 50 Won. T&C ratings were validated against a reference standard based on physician`s diagnosis. Test-retest reliability and inter-observer reliability were assessed. RESULTS: The T&C test had a sensitivity of 73.0%, specificity of 90.9%, positive predictive value of 93.1%, and negative predictive value of 66.7%. Test-retest and inter-observer agreement rates were 95% and 95%, respectively. The T&C test was not influenced by education. The time and change tests took a mean of 7.5 seconds and 19.6 seconds to complete respectively, and was acceptable to participants. When timed cut points were added, the T&C test had a sensitivity of 86.5%, specificity of 40.9% and test-retest and inter-observer agreement rates were 77.3% and 81.8%, respectively. CONCLUSION: The T&C test is a simple, accurate reliable, performance-based tool for detection of dementia in the elderly.